The means used for attachment of an aerial bomb to a bomb rack and its release mechanism has generally remained the same since commencement of aerial bombardment. This suspension attachment has taken the form of a fixed lug screwed into the body or shell of the bomb and projecting outward from the bomb surface. When the concept of a fixed lug was introduced, aerodynamic drag of the lug on the bomb was not an important factor. The launch speed of the bomb was low, and bomb sight accuracy was not well developed. A deviation in the path of the free-falling bomb due to the unsymmetrical drag force created by suspension lugs projecting outward from the surface of the bomb was not considered detrimental to the mission under such conditions.
Drag effects of suspension lugs have assumed more importance with the higher launching speeds of present day high-performance aircraft and sophisticated high-precision bombing systems that make use of improved bomb sights with the capability to compensate for conditions which can affect the path of the falling bomb by calculating the exact moment for release responsive to those conditions. To take full advantage of precision bombing technology, a need exits to reduce or eliminate unsymmetrical drag forces produced by conventional suspension lugs.
Various retractable lug devices for missiles are disclosed in prior art patents. A prior art patent, U.S. Pat. No. 3,967,529, issued July 6, 1976, to Ingle et al., shows a missile wherein supporting lugs are retracted into the body of the missile after launch by action of biasing springs. This device is not applicable to bomb lugs in that it depends upon the action of launcher rails that remain with the launch platform. U.S. Pat. No. 4,170,923, issued Oct. 16, 1979, to Kilmer, also shows an assembly for retracting missile launch lugs out of the airstream after launch, but this device would likewise not be adaptable for bomb suspension lugs.